


Substitute

by SilvorMoon



Category: Yu-Gi-Oh! VRAINS
Genre: Flirting, M/M, Post-Canon, School
Language: English
Status: Completed
Published: 2020-02-12
Updated: 2020-02-12
Packaged: 2021-02-27 20:21:36
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,917
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22671700
Author URL: https://archiveofourown.org/users/SilvorMoon/pseuds/SilvorMoon
Summary: Yusaku has to go to school, and Ai doesn't want to be left behind. Unfortunately, only students are allowed to attend school... right?
Relationships: Ai | Ignis/Fujiki Yuusaku
Comments: 3
Kudos: 70





	Substitute

Yusaku liked to think of himself as a logical person. Anything he attempted, he went about in a calm, methodical manner, with all his moves planned well in advance, and with contingency plans in place if the first plans went wrong. He did not think of himself as easily moved by emotional appeals. The way to move him was with reason, not impassioned pleas. 

All the same, he was finding this argument very hard going. 

“But I’ll _miss_ you,” Ai was saying. 

And how could you argue with that? The problem was that Yusaku had missed Ai dreadfully while he had been gone. He had been sure he would never _stop_ missing him. When they had learned that Ai wasn’t really gone, that his data was still safe somewhere out there in the network, that they could actually find him and bring him back... well, that had seemed like a miracle. It still felt like a miracle - after all, it had only been a few days since they’d gotten him and the others back, and Yusaku was still astonished to wake up every morning and discover that Ai was there waiting for him. If he had been free to choose, he would have gladly spent the whole day with Ai. 

“I’ll miss you too,” he said, with genuine regret. “But I really can’t skip any more school.” 

“So take me with you,” said Ai. 

“Not while you’re still in that SOLtis body,” said Yusaku sternly. 

Ai groaned. “I don’t wanna spend the whole day stuffed down your backpack.” 

“Well, those are your choices,” said Yusaku implacably. “Either you go in your small form or you don’t go.” 

Ai pouted. “You’re no fun. I’d have thought you’d be more grateful to have me around.” 

“I am,” said Yusaku, letting his voice soften a bit. “And if you can figure out a way to go to school like this without getting us both in trouble, I won’t complain. I just don’t see what that would be.” 

“Can’t I be a student?” 

“I doubt it. You look a bit old for school. If you wanted to be a student, you should have chosen to look more like Roboppy.” 

“Humph,” said Ai. He cast a jaundiced look at Roboppy, who was in the process of cleaning Yusaku’s breakfast dishes. “I don’t suppose you want to go to school too, do you?” 

“Nope!” he said cheerfully. “Who wants to go to school when they don’t have to?” 

“See, there you go,” said Yusaku. “I’m going to be bored all day. At least you can watch TV. Play video games. Keep Roboppy company. Go for a walk or something. Just stay out of trouble, all right?” 

“Fiiiine,” said Ai with an exaggerated sigh. He let himself flop back onto sofa and draped an arm across his face, in a gesture that was clearly supposed to convey that he was perishing of loneliness already. It made Yusaku smile. 

“You’re so dramatic,” he said. “You should go into acting.” 

“Maybe I will,” said Ai, not moving. “I will become the beloved star of stage and screen, and then you’ll be sorry you abandoned me.” 

“You do that,” said Yusaku, stifling a laugh. “I’m going to school. See you later.” 

Yusaku left for school in a good mood. Bantering with Ai was a good way to start the day. 

For a while, all was quiet in the apartment. Roboppy finished with the dishes and started sweeping the floor. At one point, he paused to gently nudge Ai’s foot out of the way so he could reach under the bed. 

“It’s not fair,” Ai complained. “I don’t see why I can’t go to school if I want to.” 

“You heard him. You’re too old,” said Roboppy cheerfully. “You should be a kid like me. Adults don’t go to school.” 

“Shaddup,” said Ai. He rearranged himself more comfortably on the bed, now that Yusaku wasn’t around to perform for. He stared up at the ceiling and let his mind wander. 

“Hmm,” he said after a while. “You know, you’re wrong about that.” 

Roboppy looked up, eyes wide and interested. “Wrong about what?” 

“About school,” said Ai. “Adults do go there.” He sat up, energized by a new idea. “Hmm... I wonder what the odds are...” 

* * *

There was something almost reassuring about being back in school. Yusaku was surprised to find that a few people were actually glad to see him again. He had spun a story about having to deal with the death of a family member (well, it was true, more or less) so people were sympathetic without being too nosy about exactly where he’d been and what he had been doing. Anyway, he never let school stress him much. He was perfectly aware that he had the skills to make a career for himself regardless of how his grades turned out. He was fairly certain that any time he wanted a job at SOLtech, he only needed to ask. He could just relax and soak up any facts that happened to reach him without worrying too much. 

Just now, he was feeling particularly unworried, because math class was about to start, and he was good at math. He might have difficulty with metaphors and symbolism, and he couldn’t always be bothered to remember the principal exports of a country he’d probably never visit, but he liked playing with numbers. He put his literature textbook away and waited expectantly. After a moment or two, he glanced at his watch. 

“Where’s Professor Furuyama?” he asked. 

As usual, Naoki had the inside scoop. 

“He’s out sick,” he said knowledgeably. “I heard it this morning when I walked past the teacher’s lounge. He fell going down some stairs and broke his ankle so he’s taking a couple of days off. We’re having a substitute today.” 

“I hope we are, anyway,” said Yusaku, looking up at the front of the room, where there were still no teachers in evidence. “I’m not sure what happens if the teacher never shows up. Do you think he got lost?” 

Naoki grinned. “Hey, buddy, you know the rule! If the teacher doesn’t get here within fifteen minutes, that means class is cancelled!” 

“I don’t think that’s a real rule,” said Yusaku, but no one paid any attention to him. 

In the end, he never found out if class would be cancelled if a teacher didn’t show, because a moment later, one did. At least, the classroom door opened, and a man walked in. The class, which had been getting boisterous in the absence of adult supervision, quieted at once. This was not a usual reaction. Normally the arrival of a substitute teacher would provoke a murmur of speculation, but just now, everyone was simply staring, Yusaku most of all. This probably had something to do with the fact that the teacher was strikingly attractive, even to the point of being a little unearthly. He was also, unmistakably, Ai. 

At least he’d had the sense to dispose of his typical ringmaster-vampire costume. He was wearing a simple gray suit and white shirt, with only the earrings and an oddly patterned black and purple tie to hint at what sartorial feats he was capable of. He didn't look substantially different from the way any other teacher in the school dressed. It was just that somehow, while other teachers looked, well, teacherly, he looked as though he'd been on his way home from a fashion shoot when he'd decided to stop and teach a math class. Even as Yusaku watched, he reached delicately into a pocket of his jacket and withdrew a pair of small rectangular spectacles. The way he unfolded one arm of them with his teeth made several girls in the class sigh and Yusaku's cheeks go red. 

_This just can't be happening,_ he thought, burning with embarrassment and somehow still unable to take his eyes off the apparition in front of him. He had thus far been successfully avoiding thinking about how attractive Ai was - after all, he knew it was basically just a projection, and not, in certain vital respects, _real_. It was just that in other, more practical ways, well... 

"Good morning, everyone!" said Ai, flashing a sunny smile around the room. "My name is Mr. Aihara, and I will be your substitute teacher for today! Everyone settle down so we can get started." 

Everyone settled down, except for Yusaku, who was quietly freaking out. 

_What is he thinking? He can't teach a math class..._

Ai picked up a sheaf of papers and glanced through them. 

"It looks like you've been studying polynomials this week," he went on. "Would anyone like to bring me up to speed about what you've been learning? How about you - yes, you on the right there. Come up to the front and see if you can explain to me the steps involved..." 

Yusaku watched, astonished, as one of the students stepped up to the whiteboard and began explaining how he would work through a sample problem, and Ai quizzed him about how he would handle slight changes in the formula. After a while, he was forced to revise his opinion: apparently, Ai _could_ teach a math class. 

_Well, I suppose it makes sense. He can do more sums in the blink of an eye than a whole roomful of people with calculators could do in an hour. This must be like teaching a toddler to count, to him._

"All right," said Ai, after he'd gone through this process with a few other students, "it seems like you've got the hang of it. I've got some worksheets here for you, so if one of you will pass them out, I'll let you work quietly for a while and walk around to help you if you get stuck. Who wants to pass out papers? How about you?" 

His finger pointed directly at Yusaku, who jumped. 

"Me?" he repeated, feeling as stupid as he'd ever felt in his life. 

"Yes, you'll do. What's your name?" Ai asked wickedly. 

"Ah... Fujiki Yusaku." 

"Well, come on down and give me a hand." 

Yusaku walked to the front of the class, aware of jealous looks from those who resented the attention he was getting from their charming new teacher. 

_If only you knew..._

He reached the teacher's desk, and Yusaku got as close as he dared to collect the papers. 

"Just what do you think you're doing?" he hissed, so quietly that even a normal human probably wouldn't have heard him. 

Ai smiled. "Coming to school, obviously." 

Yusaku would have liked to argue, but he didn't dare talk too long. For one thing, he was afraid he'd lose his temper and start shouting. Instead, he took the papers and began handing them out, trying to pretend that this was all very normal and not as though he was clenching his teeth so hard they creaked. 

At least things settled down once the worksheets were handed out. Yusaku sat down and began filling them out, letting the work absorb his mind. Out of the corner of his eye, he watched Ai stroll up and down the aisles. He was slightly surprised at how seriously Ai seemed to be taking this. He was pausing, here and there, to speak to a student who seemed to be struggling, or to point out a mistake. It was a little uncanny the way he was able to see at a glance whether someone had transposed a number or misplaced their parentheses, but the class seemed prepared to believe he was some kind of numerical genius. 

_Well, they're not entirely wrong._

He had been in the depths of a particularly complex problem when he became aware of a shadow over him. He looked up to see Ai grinning down at him. 

"Are you wearing cologne?" Yusaku whispered. 

"I decided to spiff myself up for my new job," said Ai cheerfully. He leaned in so close that his hair tickled Yusaku's cheek. "Smells nice, doesn't it?" 

It did. Yusaku was annoyed to feel his face going hot again and resisted the urge to give Ai a shove. 

"Can you even smell?" he asked instead. 

Ai just grinned. "You forgot to carry the two, there." 

Yusaku looked down where Ai was pointing. He looked up again and scowled. "You were distracting me." 

"Good. I like distracting you.' 

And he breezed off again, leaving Yusaku wishing he were allowed to punch teachers. Even after Ai was gone, the scent of his cologne lingered, smelling of oranges and spice and making him giddy. 

It was a relief when the bell finally rang for lunch. Ai gathered up the papers and swept off. Yusaku, who'd finished his worksheet quickly out of sheer spite, had already gathered his things together and contrived to be one of the first people out of class. As he'd hoped, most of his classmates were eager to get to the cafeteria, no matter how fascinated they might be by their glamorous new instructor, so no one seemed to notice when the reclusive Yusaku separated himself from the main crowd and followed closely after Ai. 

They ended up in the computer lab - empty at the moment, since everyone who might have been using it had gone to lunch. Once they were inside, Yusaku took the precaution of locking the door behind them. Ai just sat on a desk in one corner and grinned a cat-who-stole-the-cream smile. 

"How did I do?" he asked. 

Yusaku whirled around to glare at him. "You idiot, you're going to get us both into trouble!" 

"Why?" Ai asked innocently. 

"Why? Because... because... because you're not really a teacher!" 

"I have paperwork that says I am," said Ai. "It was easy to make." 

Yusaku was mildly aghast. “I’m pretty sure that’s illegal.” 

“So? What are they going to do, put me in jail?” 

That was a point. It wasn’t as though he needed the body he was in just now. At the drop of a hat, he could retreat into the network and sweep up his tracks behind him, so that not even the best computer expert in the world would be able to follow him. 

“How exactly,” he said at last, “did you manage to do this? _Why_ did you do this?” 

“Well, you said I couldn’t come to school with you like this unless I figured out some way to do it without being noticed,” said Ai plausibly, “so I thought about it, and I thought, it isn’t just kids who go to school, right? It’s teachers and things too. I knew I couldn’t get away with pretending to be part of the regular staff, but a substitute teacher... well that’s different. So I did a little poking around and found out your math teacher wasn’t going to be in today, so I created some credentials and made a phone call or two and voila! Here I am.” 

Yusaku looked at him with that expression that was starting to become commonplace: part awe, part horror, part utter exasperation. This time, though, he was actually slightly touched, too. 

“And you’ve just been giving math lessons all day?” he asked. 

“Sure. Why not? It’s pretty fun, actually,” said Ai. “Math is easy, and I like having everyone paying attention to me.” 

Yusaku laughed and shook his head. “You would, wouldn’t you?” 

“Well, why wouldn’t I?” asked Ai, preening a little. “I am extremely interesting, and also exceptionally good-looking. I am brightening everyone’s day by being here. People ought to pay attention to me.” 

“You are really something else,” said Yusaku, but he was still smiling. “Well, I shouldn’t say it, but I’m actually kind of glad you’re here.” 

Ai grinned. “So you won’t mind if I decide to sub again sometimes?” 

“Well... maybe every once in a while is okay,” said Yusaku, giving in. After all, he seemed to be good at it, he was enjoying it, and there didn’t seem to be any way of stopping him. “Just don’t get carried away.” 

Ai grinned. “And when do I ever do that?” 

Yusaku rolled his eyes and shoved him, and Ai laughed, unrepentant. 

“Now, I’d better get going,” said Yusaku. “Before people start thinking you’re carrying on an affair with a student.” 

Ai grinned wickedly. He leaned in close and kissed Yusaku lightly on the tip of his nose. 

“Maybe I am,” he said. 

Yusaku was sure he was going red from his scalp to his collarbone. For a few seconds, he absolutely couldn’t think of anything to say. 

Then Ai laughed and turned away. Even wearing a conservative gray suit, he still managed to give the impression of a swirling cape when he moved. Yusaku noticed that he had his hair pulled back in a ponytail, and had a powerful urge to pull it free and smooth it back into its customary place with his fingers. 

_Well, maybe later,_ he thought. It was an oddly cheerful thought. If Ai was going to spend the whole day flirting with him, he ought to be prepared for Yusaku to respond in kind. 

“Hey, Ai?” he called. 

Ai paused on the way to the door and looked back expectantly. “Yes?” 

“You should wear those glasses more often. They suit you.” 

Ai beamed. 

“Maybe just for you,” he said, and winked. 

Then he was gone, practically skipping as he flitted away. Yusaku smiled, feeling inexplicably pleased with himself. 

_Well,_ he thought, _It looks as though school is about to become more interesting._


End file.
